Merge pull request #599 from wordpress-mobile/update/version-number

Update version to 1.38.0-beta.4

Author: shiki

WordPressAuthenticator.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name          = "WordPressAuthenticator"
-  s.version       = "1.38.0-beta.3"
+  s.version       = "1.38.0-beta.4"
 
   s.summary       = "WordPressAuthenticator implements an easy and elegant way to authenticate your WordPress Apps."
   s.description   = <<-DESC